Water-tube boiler.



N0. 729,738 PATENTED JUNE 2, 1903..

' J. comm.

WATER TUBE BOILER.

APPLICATION I'ILBD OUT. 3,1901.

no MODEL. s snnmwsns w 1k PATENTED JUNE 2, 1903.

\ J. GOWAN.

WATER TUBE BOILER.

v -APPLIUATION FILED OUT. 3, 1901. 7

NO MODEL. 3 SHEETS-SHEBT 2.

No; 729,738. PATENI'BD JUNE 2,1903.

" J. GOWAN.

WATER TUBE BOILER. APPLICATION FILED 00%. s, 1901.

110 MODEL. s snnE rs-snnnrs.

Patented June 2, 1903.

ATENT OFFICE.

JOHN OOWAN, OF EDINBURGH, SCOTLAND.

WATER-TUBE BOILER.

SPECIFICATION forming part of Letters Patent N 0. 729,738, dated June 2, 1903.

Application filed October 3. 1901. Serial No. 77,456. (No model.)

To all whmn it may concern.-

Beit known that I, JOHN OOWAN, managing director of The Stirling BoilerOompany, Limited, a subject of the King of Great Britain and Ireland,residing at 2 St.Andrews Square, Edinburgh, Scotland, have invented certain new and useful Improvements in Water-Tube Boilers, (for which I have made application for patent in Great Britain, No. 9,924, dated May 13, 1901,) of which the*following is a specification. I

My invention relates to water-tube boilers, especially the Stirling type of boiler.

The unsteady motion to which marine boilers are subjected tends to produce agitation of the Water in the drums and consequent wetness of the steam and priming, and even in land-boilers of approved construction these evils may occur when water having a frothy tendency is used.

The object of my invention is to increase the dryness of steam generated under ordinary conditions and to insure the production of dry steam under such adverse conditions as those above referred to.

My invention consists also in increasing the effective distance between the water-level in the boiler and the steam-outlet pipe by providing a boX partition or baffle within a drum from which steam is drawn and in arranging the steam-outlet to draw from this pocket only, the pocket being arranged to be fed with steam only from or through one or more of the other drums, whereby the steam is thoroughly dried before it leaves the steam-outlet. Myinvention also consists in increasing the effective distance between the water-level and the steam-pipes which connect the drums by means of suitable baffles, as hereinafter described.

Referring now to the accompanying drawings, Figure 1 is a sectional side elevation of a Stirling boiler with my invention applied.

Fig. 2 is an end viewof the same, the lefthand half being a section on the line X X of Fig. 1 with the fire-grate removed. Fig. 3 is a plan of the drums. and connecting-tubes only,showing the baflies and the steam-pocket in dotted lines.

In the figures I have shown my invention applied to a Stirling boiler constructed with three upper steam and waterdrums a, b, and 0,

connected to a single lower water-drum d by banks of tubes e, f, andg. The drums a, b, and c are connected together above the waterlevel by steam-tubes t and u and below the water-level by tubes .9 and q. The waterspace of the drum 0 is divided into two spaces by the partition 01, and the drum d is divided by a partition 72, into two spaces j and 75, into the latter of which the feed-water from the feed-pipe r in the drum 0 is passed by way of the tubes 19. Communication between the spaces j and is efiected through holes m in the partition 7t. As, however, this boiler forms the subject of a separate application, it is not necessary to further describe it in the present application.

In applying myinvention according to one modification to a boiler of the above description I provide the central drum I) with a boxbafiie 9r pocket w, secured to the inside of the drum above the' water level. The main steam stopvalve a; and a certain section of the steam-tubes u, (lettered .2 on Figs. 2 and 3,) communicate directly with this pocket 10, which is shut off" from the rest of the steamspace of the drum 1). By means of this device the steam generated in the front drum a must pass through the pipes 15 i nto the central dru m b on its way to the stop-valve on. It cannot, however, pass direct to the stop-valvefrom this drum 1), since the pocket closes off the steamoutlet; but it passesthrough the steam-pipes u, which are not included inthe pocket, into the feed drum 0, whence it passes by the tubes 2 into the pocket 20 and out through the stop-valve 0a to the engine in the manner indicated by the arrows in Fig. 3. The various changes in the direction of steam-flow caused by this steam circulation produces a drying effect on the steam similar to that produced by steam-separators. This arrangement also increases the effective distance between the outlet 00 and the water-level practically to that between the level of the water in the back drum 0 through the steam-pipes and the outlet w. n

I increase the effective distance between the water-level in the drums a and c andthe connecting-pipes t, u, and z by means of inclined baffles or troughs 2, 2, and 3, respectively, secured to the inside of the drums a, b, and c opposite the mouths of the tubes connecting the steam-spaces of the drums, the baffle 2 extending along the whole length of the drum a, the baflles 2 occupying the spaces on each side of the box to opposite the tubes "u, in the drum 5, and the baffles 3 opposite the mouths of the central section z of the tubes 'Ltlfl thedrum c. The trough 2 extends the whole Width of the tubes 15; but the trough 3 obviously need only be the width of the section a of tubes u.

The troughs may be provided with a suitable drain-pipe or'with holes to prevent the possibility of water lodging in them.

The whole boiler may be inclosed in a suitable casing, baliles being provided to direct the furnace-gases among the tubes in the most advantageous manner to an uptake 4, situated between [\\0 of the steam and water drums or in any other suitable position.

A boiler thus constructed is well adapted for marine purposes and other cases where space is valuable and lightness desired, While the production of dry steam under the most adverse circumstances is assured.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

p 1. In a water-tube boiler constructed with a plurality of steam and water drums the steam-spaces of which are in communication with each other, in combination, an internal pocket secured opposite the steam-outlet inside one of the steam-spaces, and tubes connecting the pocket with one of the other steam-spaces, whereby the steam from all the drn ms is caused to pass through these tubes into the pocket before passing through the steam-outlet, substantially as described.

2. In a water-tube boiler constructed with a plurality of steam and water drums the steam-spaces of which are in direct communication with each other, in combination, an internal pocket secured opposite the steam-outlet inside one of the steam -spaces, steamtnbes connecting the pocket with one of the other steam-spaces, and open-topped troughs secured to the inside of the drums opposite the mouths of the steam-tubes, substantially as described.

In witness whereof I have hereunto set my hand in presence of two witnesses.

. JOHN COWAN.

\Vitnesses:

J AMES BAIRD, W. \V. CRocKER. 

